Surface Reactivity of Iron Silicide

The interaction of iron silicide with oxygen has been studied under ultrahigh vacuum conditions by means of X-ray photoelectron spectroscopy (XPS). The XP spectra show unambiguously that oxygen reacts with silicon in the FeSi 2 compound. The O1s XP spectra point to a formation of at least two suboxide species SiO x (x < 2) at room temperature. At higher temperatures increasing sharper signals indicate the transition to one suboxide species.